When planning kitchen lighting, consider additional task lighting for your countertops. No matter what type of overhead lighting you install in your kitchen, your kitchen wall cabinets will cast shadows over the counter. Installing lighting under your kitchen cabinets removes the shadows and brightens the countertop work surfaces. Fluorescent lighting works well for this type of lighting application, as it does not add heat to the work surface and is energy-efficient. Some prior electrical knowledge is beneficial in installing under-cabinet lighting.
Mark the location for your under-cabinet lighting. Placing lights against the wall provides a wall-washing effect. Placing the lights at the centre or the front of the kitchen cabinet provides more task lighting.
Turn off the circuit breaker to the electrical sockets above your kitchen countertops. Choose an outlet directly beneath the first cabinet under which you plan to install lighting, to use as a power source.
Test the outlet you're using as a power source to confirm the electricity is disconnected. Insert the non-contact voltage tester into the outlet slots. The tester won't light if there isn't any electrical power present.
Remove the outlet cover plate and release the outlet from the electrical box by removing the top and bottom screws. Verify there is no power present on any wire in the electrical box by touching each wire with the non-contact voltage tester. Loosen the screws holding the black, white and bare copper wires to the outlet and remove them, releasing the outlet.
Remove the screws holding the electrical socket box in the wall. If the box is attached with nails, place a piece of wood inside the box and strike it with a hammer to loosen the box and remove it from the wall. Take care not to damage the wires., As you pull the box from the wall, pull the wires into the room.
Enlarge the outlet opening to accommodate a double gang electrical box. Place the template provided with a double gang remodel box over the original outlet opening and trace around it. Cut around the electrical box's trace lines and remove the drywall with a drywall saw.
Make a nickel-sized hole in the drywall directly above the power source location, directly beneath the bottom of the wall cabinet. Feed a length of 12/2 non-metallic (NM) electrical cable through the hole and out the power source opening.
Disassemble your under-counter light fixtures, removing the lens and the fluorescent tubes. Install the fixtures beneath the cabinets with wood screws. Make sure the screws don't go up through the bottom of the cabinets.
Place a screwdriver against the 1/2-inch knockouts on the ends of the fixtures. Strike the screwdriver with a hammer to remove the knockouts. Remove the knockouts from both sides of the middle fixtures, leaving the outside knockouts intact on the two fixtures located on each end of the cabinets.
Install 1/2-inch clamp connectors into the knockouts you removed from the light fixtures. Insert the threaded ends of the connectors into the fixture and secure them with the locknuts provided with the connectors.
Drill 1/2-inch holes through the bottom of the kitchen cabinet bases with a 1/2-inch wood drill bit, allowing you to run the electrical cable from one fixture to the next.
Run lengths of 12/2 NM electrical cable from each fixture to the next, threading the cable through the clamp connectors. Insert the cable from the electrical socket location into the first under-cabinet light fixture at the connector.
Remove the sheath from the electrical cable at each under-cabinet fixture with a dual NM wire cutter/stripper. Strip 3/4 inch of insulation from the black and white wires at each fixture.
Twist a red wire connector onto the black wire from the fixture, connecting it with the two black wires from the electrical cables. Twist another wire connector onto the white wire from the fixture, connecting it to the two white wires from the electrical cables. Repeat the connection with the green wire from the fixture and the two bare copper wires from the cables. Repeat the wire connections at each fixture under the cabinets.
Tighten the two screws on each clamp connector to hold the electrical cables to the fixtures. Assemble each fixture, replacing the fluorescent tubes and lens. Secure the cable under the cabinets with one-hole 12/2 NM straps. Use wood screws to hold the straps to the underside of the cabinets.
Pull all the electrical cables through the knockouts in the double gang remodel electrical box. Push the box into the hole in the drywall and turn both screws on the box clockwise to clamp the double gang box to the wall.
Cut five, 6-inch 12-gauge solid THHN electrical wire pigtails--two black, one white and two green. Strip 3/4 inch of insulation from both ends of each pigtail.
Move the black wire from the first under-cabinet light away from the remaining wires inside the electrical box. Twist a red wire connector onto the remaining black wires inside the box, connecting them with the two black pigtail wires.
Twist a red wire connector on all the white wires inside the electrical box, connecting those wires to the white pigtail wire. Twist another red connector onto the bare copper wires, connecting the copper wires to the green pigtail wires.
Wrap the black wire from the first under-cabinet light around a screw on the right side of the light switch. Wrap one of the black pigtail wires around the remaining screw on the right side of the switch and tighten the screws.
Connect the remaining pigtail around the brass screw on the right of the outlet you removed in Step 4. Connect the white pigtail around the silver screw on the left side of the outlet. Connect the green pigtails to the green ground screws at the bottom of both the outlet and switch. Tighten all the outlet's screws.
Push the switch and outlet into the double gang electrical remodel box, attaching the top and the bottom of both the outlet and switch to the box. Cover the switch and outlet with a single switch/duplex wall plate.
Turn on the circuit breaker to the electrical sockets and the under-cabinet lighting.